Pembrolizumab in Patients With Microsatellite Instability–High Advanced Endometrial Cancer: Results From the KEYNOTE-158 Study

PURPOSE Pembrolizumab demonstrated durable antitumor activity in patients with previously treated, advanced microsatellite instability–high or mismatch repair–deficient (MSI-H/dMMR) tumors, including endometrial cancer, in the nonrandomized, open-label, multicohort, phase II KEYNOTE-158 study ( NCT02628067 ). We report efficacy and safety outcomes for patients with MSI-H/dMMR endometrial cancer enrolled in KEYNOTE-158. METHODS Eligible patients from cohorts D (endometrial cancer, regardless of MSI-H/dMMR status) and K (any MSI-H/dMMR solid tumor, except colorectal) with previously treated, advanced MSI-H/dMMR endometrial cancer received pembrolizumab 200 mg once every 3 weeks for 35 cycles. The primary end point was objective response rate per RECIST version 1.1 by independent central radiologic review. Secondary end points included duration of response, progression-free survival, overall survival, and safety. RESULTS As of October 5, 2020, 18 of 90 treated patients (20%) had completed 35 cycles of pembrolizumab and 52 (58%) had discontinued treatment. In the efficacy population (patients who received ≥ 1 dose of pembrolizumab and had ≥ 26 weeks of follow-up; N = 79), the median time from first dose to data cutoff was 42.6 (range, 6.4-56.1) months. The objective response rate was 48% (95% CI, 37 to 60), and median duration of response was not reached (2.9-49.7+ months). Median progression-free survival was 13.1 (95% CI, 4.3 to 34.4) months, and median overall survival was not reached (95% CI, 27.2 months to not reached). Among all treated patients, 76% had ≥ 1 treatment-related adverse event (grades 3-4, 12%). There were no fatal treatment-related events. Immune-mediated adverse events or infusion reactions occurred in 28% of patients (grades 3-4, 7%; no fatal events). CONCLUSION Pembrolizumab demonstrated robust and durable antitumor activity and encouraging survival outcomes with manageable toxicity in patients with previously treated, advanced MSI-H/dMMR endometrial cancer.

Lenvatinib and pembrolizumab in the treatment of metastatic endometrial cancer: literature review and case report

In 2019 in Russia endometrial carcinoma was diagnosed in 27151 patients, 6820 women died from the disease. The standard of frontline therapy for patients with advanced endometrial carcinoma is platinum and taxane-based chemotherapy with satisfactory efficacy – the median progression-free survival is about 13 months, and up to 50% of patients achieve objective response to therapy. On the other hand, for patients with recurrent endometrial cancer after frontline chemotherapy the results of chemotherapy remained generally unsatisfactory, the objective response rate to standard treatment was about 10 to 15%. During the last few years there significant progress has been made in this area – studies identified a subgroup of patients with a high level of microsatellite instability (MSI-high) highly sensitive to pembrolizumab therapy. In this subset of patients, who account for up to 25% of patients with metastatic endometrial cancer, the objective response rate to pembrolizumab monotherapy is up to 57%. Further studies have shown that the addition of lenvatinib to pembrolizumab therapy may be a highly effective therapeutic option for patients without MSI-high. This article describes a clinical case of the successful therapy of a patient with platinumresistant endometrial carcinoma with a combination of pembrolizumab and lenvatinib.

Circulating tumor DNA-guided treatment with pertuzumab plus trastuzumab for HER2-amplified metastatic colorectal cancer: a phase 2 trial

The applicability of circulating tumor DNA (ctDNA) genotyping to inform enrollment of patients with cancer in clinical trials has not been established. We conducted a phase 2 trial to evaluate the efficacy of pertuzumab plus trastuzumab for metastatic colorectal cancer (mCRC), with human epidermal growth factor receptor 2 (HER2) amplification prospectively confirmed by tumor tissue or ctDNA analysis (UMIN000027887). HER2 amplification was confirmed in tissue and/or ctDNA in 30 patients with mCRC. The study met the primary endpoint with a confirmed objective response rate of 30% in 27 tissue-positive patients and 28% in 25 ctDNA-positive patients, as compared to an objective response rate of 0% in a matched real-world reference population treated with standard-of-care salvage therapy. Post hoc exploratory analyses revealed that baseline ctDNA genotyping of HER2 copy number and concurrent oncogenic alterations adjusted for tumor fraction stratified patients according to efficacy with similar accuracy to tissue genotyping. Decreased ctDNA fraction 3 weeks after treatment initiation associated with therapeutic response. Pertuzumab plus trastuzumab showed similar efficacy in patients with mCRC with HER2 amplification in tissue or ctDNA, showing that ctDNA genotyping can identify patients who benefit from dual-HER2 blockade as well as monitor treatment response. These findings warrant further use of ctDNA genotyping in clinical trials for HER2-amplified mCRC, which might especially benefit patients in first-line treatment.

ADAGIO: a phase IIb international study of the Wee1 inhibitor adavosertib in women with recurrent or persistent uterine serous carcinoma

BackgroundUterine serous carcinoma is a distinct histologic subtype of endometrial cancer with an aggressive phenotype, poor prognosis, and limited therapeutic options. A previous proof-of-concept phase II trial of the Wee1 inhibitor adavosertib in uterine serous carcinoma demonstrated evidence of durable clinical activity.Primary ObjectiveTo evaluate the efficacy of adavosertib in women with recurrent or persistent uterine serous carcinoma.Study HypothesisWe hypothesize that adavosertib will demonstrate significant clinical activity, as measured by objective response rate, in women with recurrent or persistent uterine serous carcinoma.Trial DesignEligible participants will receive adavosertib monotherapy until disease progression or unacceptable toxicity, starting at the recommended phase II dosing of adavosertib 300 mg daily days 1 through 5 and 8 through 12 of a 21-day cycle. Participants will have restaging studies every 6 weeks for the first 48 weeks and then every 9 weeks thereafter.Major Inclusion/Exclusion CriteriaPatients with histologically confirmed recurrent or persistent uterine serous carcinoma, including endometrial carcinoma of mixed histology where the serous component comprises at least 10% of the tumor, and who have received at least one prior platinum-based chemotherapy regimen for the management of uterine serous carcinoma, are eligible for inclusion in the trial. Participants must have measurable disease by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria. Participants with carcinosarcoma are not eligible.Primary EndpointThe primary endpoint is the objective response rate by RECIST 1.1 criteria, as determined by blinded independent central review.Sample SizeApproximately 120 patients will be enrolled in this trial.Estimated Dates for Completing and Presenting ResultsStudy completion and presentation of results are projected to be at the end of 2022.Trial RegistrationClinicalTrials.gov: NCT04590248.

Expression of FOXA1 Is Associated with the Tumor-Infiltrating M2 Macrophage, Cytotoxic T Lymphocyte, and Effect of Chemotherapy in Bladder Cancer

Purpose: Cisplatin-containing combination chemotherapy has been the standard of care since the late 1980s, but the response rate is <50%. Studies have shown that the efficiency of chemotherapy differs among molecular subtypes of bladder cancer. In this study, we aimed to correlate FOXA1, a marker for differentiation of the basal and luminal subtypes, with tumor immune cell infiltration and the effect of chemotherapy in bladder cancer. Materials and Methods: Eighty-three patients with bladder cancer treated with chemotherapy were reviewed. Clinicopathological variables for each case were recorded. FOXA1, M2 tumor-associated macrophage (TAM), dendritic cell (DC), and cytotoxic T lymphocyte (CTL) were examined by immunohistochemistry. The relationship between FOXA1, immune cell infiltration, and clinical response to chemotherapy was assessed. Results: The overall objective response rate was 34%. The objective response rate for tumors with lower FOXA1 expression was 58% and for tumors with higher FOXA1 expression was 12%. Tumors with infiltrated M2 TAM proportion <3% had a higher objective response rate compared with infiltrated M2 TAM proportion >3% tumors (46% vs. 21%, p = 0.02). Tumors with infiltrated CTL proportion >5% had a higher objective response rate compared with infiltrated CTL proportion <5% tumors (50% vs. 17%, p = 0.002). DCs showed no significant differences. We found that the objective response rate for tumors with lower FOXA1 expression, proportion <3% M2 TAM infiltration, and proportion >5% CTL infiltration is 82%. Lower FOXA1 expression was associated with low M2 TAM infiltration and high CTL infiltration. Conclusions: Thus, we showed that in patients with bladder cancer who received chemotherapy, the higher clinical response rate is associated with low FOXA1 expression, low M2 TAM infiltration, and high CTL infiltration.

First-Line Nivolumab Plus Low-Dose Ipilimumab for Microsatellite Instability-High/Mismatch Repair-Deficient Metastatic Colorectal Cancer: The Phase II CheckMate 142 Study

PURPOSE Nivolumab received US Food and Drug Administration approval as a single agent or in combination with ipilimumab in patients with microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC) that progressed following treatment with a fluoropyrimidine, oxaliplatin, and irinotecan based on CheckMate 142. Presented are results of nivolumab plus low-dose ipilimumab in the first-line therapy cohort from the phase II CheckMate 142 study. PATIENTS AND METHODS Patients with no prior treatment in the metastatic setting for MSI-H/dMMR CRC were treated with nivolumab every 2 weeks plus low-dose ipilimumab every 6 weeks until disease progression. The primary end point was objective response rate (investigator assessment; RECIST v1.1). RESULTS Median age of treated patients was 66 years (N = 45). Median follow-up was 29.0 months. Objective response rate and disease control rate were 69% (95% CI, 53 to 82) and 84% (95% CI, 70.5 to 93.5), respectively, with 13% complete response rate. Median duration of response was not reached; 74% of responders had ongoing responses at data cutoff. Median progression-free survival and median overall survival were not reached with minimum follow-up of 24.2 months (24-month rates, 74% and 79%, respectively). Clinical benefit was observed regardless of baseline demographic and tumor characteristics, including BRAF or KRAS mutation status. In a post hoc analysis, of 14 patients who discontinued treatment and did not receive subsequent therapy, 10 remained progression-free. Patient-reported outcomes were stable over the treatment period. Grade 3-4 treatment-related adverse events occurred in 22% of patients; 13% discontinued because of any-grade treatment-related adverse events. CONCLUSION Nivolumab plus low-dose ipilimumab demonstrated robust and durable clinical benefit and was well tolerated as a first-line treatment for MSI-H/dMMR mCRC. Based on these promising data, randomized studies are warranted.

Phase 2 study of axicabtagene ciloleucel in Japanese patients with relapsed or refractory large B-cell lymphoma

Background Axicabtagene ciloleucel (axi-cel) is an autologous chimeric antigen receptor T-cell based anti-CD19 therapy. The ZUMA-1 study, multicenter, single-arm, registrational Phase 1/2 study of axi-cel demonstrated high objective response rate in patients with relapsed/refractory large B-cell lymphoma. Here, we present the results of the bridging study to evaluate the efficacy and safety of axi-cel in Japanese patients (JapicCTI-183914). Methods This study was the phase 2, multicenter, open-label, single-arm trial. Following leukapheresis, axi-cel manufacturing and lymphodepleting chemotherapy, patients received a single infusion of axi-cel (2.0 × 106 cells/kg). Bridging therapy between leukapheresis and conditioning chemotherapy was not allowed. The primary endpoint was objective response rate. Results Among 17 enrolled patients, 16 received axi-cel infusion. In the 15 efficacy evaluable patients, objective response rate was 86.7% (95% confidence interval: 59.5–98.3%); complete response/partial response were observed in 4 (26.7%)/9 (60.0%) patients, respectively. No dose-limiting toxicities were observed. Grade ≥ 3 treatment-emergent adverse events occurred in 16 (100%) patients—most commonly neutropenia (81.3%), lymphopenia (81.3%) and thrombocytopenia (62.5%). Cytokine release syndrome occurred in 13 (81.3%) patients (12 cases of grade 1 or 2 and 1 case of grade 4). No neurologic events occurred. Two patients died due to disease progression, but no treatment-related death was observed by the data-cutoff date (October 23, 2019). Conclusion The efficacy and safety of axi-cel was confirmed in Japanese patients with relapsed/refractory large B-cell lymphoma who have otherwise limited treatment options. Trial registration JapicCTI-183914.

Poziotinib for Patients With HER2 Exon 20 Mutant Non–Small-Cell Lung Cancer: Results From a Phase II Trial

PURPOSE Targeted therapies against non–small-cell lung cancer (NSCLC) harboring HER2 mutations remain an unmet need. In this study, we assessed the efficacy and safety of poziotinib in patients with HER2 exon 20 mutant advanced NSCLC in a single-arm, open-label, phase II study. PATIENTS AND METHODS Patients with advanced HER2 exon 20 mutant NSCLC were enrolled to receive poziotinib at a dose of 16 mg/d for 28-day cycles. The primary end point was objective response rate per RECIST version 1.1. Confirmatory scans were performed at least 28 days from initial radiologic response. RESULTS Thirty patients received poziotinib treatment. At baseline, 90% of patients received prior platinum-based chemotherapy and 53% had two lines or more prior systemic therapies. As of data cutoff on March 1, 2021, the confirmed objective response rate was 27% (95% CI, 12 to 46). Responses were observed across HER2 exon 20 mutation subtypes. The median duration of response was 5.0 months (95% CI, 4.0 to not estimable). The median progression-free survival was 5.5 months (95% CI, 4.0 to 7.0). The median overall survival was 15 months (95% CI, 9.0 to not estimable). The most common grade 3 treatment-related adverse events were skin rash (47%) and diarrhea (20%). There was one possible treatment-related death because of pneumonitis. CONCLUSION Poziotinib showed promising antitumor activity in patients with HER2 exon 20 mutant NSCLC including patients who had previously received platinum-based chemotherapy.

E2112: Randomized Phase III Trial of Endocrine Therapy Plus Entinostat or Placebo in Hormone Receptor–Positive Advanced Breast Cancer. A Trial of the ECOG-ACRIN Cancer Research Group

PURPOSE Endocrine therapy resistance in advanced breast cancer remains a significant clinical problem that may be overcome with the use of histone deacetylase inhibitors such as entinostat. The ENCORE301 phase II study reported improvement in progression-free survival (PFS) and overall survival (OS) with the addition of entinostat to the steroidal aromatase inhibitor (AI) exemestane in advanced hormone receptor (HR)–positive, human epidermal growth factor receptor 2 (HER2)–negative breast cancer. PATIENTS AND METHODS E2112 is a multicenter, randomized, double-blind, placebo-controlled phase III study that enrolled men or women with advanced HR-positive, HER2-negative breast cancer whose disease progressed after nonsteroidal AI. Participants were randomly assigned to exemestane 25 mg by mouth once daily and entinostat (EE) or placebo (EP) 5 mg by mouth once weekly. Primary end points were PFS by central review and OS. Secondary end points included safety, objective response rate, and lysine acetylation change in peripheral blood mononuclear cells between baseline and cycle 1 day 15. RESULTS Six hundred eight patients were randomly assigned during March 2014-October 2018. Median age was 63 years (range 29-91), 60% had visceral disease, and 84% had progressed after nonsteroidal AI in metastatic setting. Previous treatments included chemotherapy (60%), fulvestrant (30%), and cyclin-dependent kinase inhibitor (35%). Most common grade 3 and 4 adverse events in the EE arm included neutropenia (20%), hypophosphatemia (14%), anemia (8%), leukopenia (6%), fatigue (4%), diarrhea (4%), and thrombocytopenia (3%). Median PFS was 3.3 months (EE) versus 3.1 months (EP; hazard ratio = 0.87; 95% CI, 0.67 to 1.13; P = .30). Median OS was 23.4 months (EE) versus 21.7 months (EP; hazard ratio = 0.99; 95% CI, 0.82 to 1.21; P = .94). Objective response rate was 5.8% (EE) and 5.6% (EP). Pharmacodynamic analysis confirmed target inhibition in entinostat-treated patients. CONCLUSION The combination of exemestane and entinostat did not improve survival in AI-resistant advanced HR-positive, HER2-negative breast cancer.

Randomized Phase II Trial of Vincristine-Irinotecan With or Without Temozolomide, in Children and Adults With Relapsed or Refractory Rhabdomyosarcoma: A European Paediatric Soft tissue Sarcoma Study Group and Innovative Therapies for Children With Cancer Trial

PURPOSE The VIT-0910 trial was conducted to evaluate efficacy and safety of the vincristine-irinotecan combination with and without temozolomide (VIT and VI, respectively) in relapsed or refractory rhabdomyosarcoma (RMS). METHODS In this randomized European phase II trial, patients age 0.5-50 years received 21-day cycles combining vincristine (1.5 mg/m2 once a day on day 1 and day 8) and irinotecan (50 mg/m2 once a day from day 1 to day 5) with and without temozolomide (125 mg/m2 once a day from day 1 to day 5 and 150 mg/m2 once a day from cycle 2), until progression or unacceptable toxicity. The primary end point was objective response rate after two cycles. Secondary end points included best response, progression-free survival, overall survival, and adverse events. A Simon 2-stage design was initially planned to separately analyze 40 patients/arm. After amendment, the trial sample size was increased to 120 and a comparison between arms, adjusted for confounding factors, was added to the statistical plan (ClinicalTrials.gov, NCT01355445 ). RESULTS Overall, 120 patients (60 per arm) were recruited in 37 European centers. The median age was 11 years (range, 0.75-45); 89% of patients had a relapsed RMS. The objective response rate was 44% (24 of 55 evaluable patients) for VIT versus 31% (18 of 58) for VI (adjusted odds ratio, 0.50; 95% CI, 0.22 to 1.12; P = .09). The VIT arm achieved significantly better overall survival (adjusted hazard ratio, 0.55; 95% CI, 0.35 to 0.84; P = .006) compared with VI, with consistent progression-free survival results (adj-hazard ratio, 0.68; 95% CI, 0.46 to 1.01; P = .059). Overall, patients experienced adverse events ≥ grade 3 more frequently with VIT than VI (98% v 78%, respectively; P = .009), including a significant excess of hematologic toxicity (81% v 61%; P = .025). CONCLUSION The addition of temozolomide to VI improved chemotherapy efficacy for patients with relapsed RMS, with manageable increase in toxicity. VIT is considered the new standard treatment in these patients in the European paediatric Soft Tissue Sarcoma Group and will be the control arm in the next randomized trial.